The present invention relates generally to the field of wire uncoilers for holding wire coils to be drawn by a wire drawing machine.
Wire or cable is typically provided from a wire manufacturer in the form of a wound spool or coil having a predetermined number of lineal feet. Such a configuration allows for relatively easy storage and transportation of wire. However, it is often necessary to cut the coiled wire into individual lengths of straight wire for commercial purposes and end use. The wire from the coils are therefore often fed into a wire cutting machine which cuts the wire into short strips for use. With such a system, the coil is placed onto a wire uncoiler which is either driven to feed the lead end of the wire coil to the wire cutter or drawn off the coil via a wire drawing machine for use.
As with many high volume production processes, this period of downtime directly relates to a loss in production and thus a loss in profits. Various attempts have been devised to provide a means of continuously feeding wire and thereby avoid downtime. One such example is provided in a wire uncoiler placed upstream of a wire drawing machine that has a Z-shaped or S-shaped configuration with parallel mandrels extending horizontally on a rotatable carousel. A wire coil is placed on one mandrel and the lead end of the wire contained in that coil is pulled by the wire drawing machine. As the wire is being pulled, the trailing end of the wire contained in the coil is manually welded to the leading end of an idle coil which is placed on the other idle mandrel. Once the active wire coil is exhausted, the carousel is rotated 180 xc2x0 and thereby makes the idle mandrel the active mandrel. The process can be continued by loading another coil onto the now idle mandrel and conducting another welding operation.
Although Z-shaped or S-shaped wire uncoilers have met with much commercial success and acceptance, they have not been without deficiencies. One existing deficiency is that it has been difficult to provide a consistent wire payoff from the wire uncoiler to the wire drawing machine. The source of this deficiency relates to the restraining arm of each mandrel, and more particularly the way in which the restraining arms restrain the bottom of the wire coil and control/guide the payoff of wire from the mandrel to the wire drawing machine. In prior systems, the restraining arm has been free floating utilizing its own weight to apply a vertically downward force to the end loop of wire and thereby control the payoff of wire. However, this has caused less consistent wire payoff because different wire gauges are used in these systems (typically in range of between {fraction (7/32)} and ⅝ inches in diameter), that drawing machines have different pull or draw characteristics, and also that wire coil characteristics can change from coil to coil for the same gauge wire (e.g. tightly or loosely coiled wire). There has been an attempt to adjust the weight at the end of the restraining arm and therefore restraining force of the restraining arm via attachable and detachable weights. However, this requires storage for the weights and limits the amount of adjustment to the weight intervals. Moreover, it is very difficult if not impossible to adjust the weight or restraining force during continuous operation, requiring downtime for weight adjustment, which is undesireable as previously indicated.
In light of the above, it is a general aim of the present invention to provide a wire uncoiler with an improved way to adjust the restraining force applied by the restraining arm.
According to one aspect of the invention, it is an object to provide a wire uncoiler with a restraining force that can be adjusted while wire is being drawn off of the mandrel.
In accordance with these and other objectives, the present invention is directed toward a wire uncoiler for holding coils of wire on mandrels for uncoiling in which the movable restraining arm is biased by a spring mechanism to control wire payoff to a downstream drawing machine. The wire uncoiler includes at least one vertical support extending vertical upward to support the mandrel horizontally at a vertical elevation. The mandrel extends horizontally to a first end where wire is adapted to be drawn off. The restraining arm extends horizontally below one of the mandrels for engaging wire coils when placed on the mandrel. The restraining arm has a second end that is vertically movable relative to the first end of the mandrel to control wire payoff from wire coils in conjunction with the first end. A spring mechanism supported by one of the vertical supports acts on the restraining arm to bias the ends of restraining arm and mandrel away from each other.
According to a preferred embodiment, the apparatus includes pairs of the mandrels on a rotary carousel that is adapted to rotate on a stationary support base. By having two or more pairs of mandrels, one mandrel can be actively paying off wire to a downstream wire drawing machine while the other mandrel is being loaded with wire. When the wire coil on the active mandrel is exhausted, the carousel can be rotated to switch the positions of the mandrels such that the idle mandrel is now active to pay off wire to the drawing machine. A worker can then load a new wire coil on the exhausted and now idle mandrel.
It is an aspect of the present invention that a manual control is provided to adjust the biasing force exerted by the spring mechanism. The manual control adapted to be manually actuated to adjust the biasing force. The manual control may include an extendible and retractable screw mechanism including a threaded shaft threaded into a threaded bore formed in a body. The screw mechanism has a first end attached to the spring mechanism and a second end adapted to be rotated to control the biasing force applied by the spring mechanism. The second end may be attached to a crank handle that can be manually grasped and rotated.
It is another aspect of present invention that the spring mechanism and the manual control are mounted to the vertical support where adjustment of the spring mechanism can be made during operation without downtime when wire is being uncoiled off of the mandrel.